US20120033705A1 - Method and device for diagnosing a thermostat - Google Patents
Method and device for diagnosing a thermostat Download PDFInfo
- Publication number
- US20120033705A1 US20120033705A1 US13/016,478 US201113016478A US2012033705A1 US 20120033705 A1 US20120033705 A1 US 20120033705A1 US 201113016478 A US201113016478 A US 201113016478A US 2012033705 A1 US2012033705 A1 US 2012033705A1
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- US
- United States
- Prior art keywords
- temperature
- thermostat
- setpoint
- fan
- measured temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 26
- 239000002826 coolant Substances 0.000 claims abstract description 44
- 238000002485 combustion reaction Methods 0.000 claims abstract description 22
- 238000001816 cooling Methods 0.000 claims description 14
- 238000003745 diagnosis Methods 0.000 abstract description 7
- 238000004364 calculation method Methods 0.000 description 11
- 238000002405 diagnostic procedure Methods 0.000 description 7
- 230000006870 function Effects 0.000 description 7
- 238000001514 detection method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 230000002950 deficient Effects 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
- F01P11/00—Component parts, details, or accessories not provided for in, or of interest apart from, groups F01P1/00 - F01P9/00
- F01P11/14—Indicating devices; Other safety devices
Abstract
In a method for diagnosing a faulty thermostat in a coolant circuit, in particular for an internal combustion engine, having a fan, the faulty thermostat is detected as a function of a measured temperature and a setpoint temperature, the fan being turned on at least temporarily during the diagnosis.
Description
- The present application claims priority to Application No. 10 2010 001 618.7, filed in the Federal Republic of Germany on Feb. 5, 2010, which is expressly incorporated herein in its entirety by reference thereto.
- The present invention relates to a method for diagnosing a thermostat, as well as to a computer program, an electrical memory medium, and a control and regulating device.
- To comply with the OBDII legislation in the United States, all exhaust-relevant components of a motor vehicle must be diagnosed by the engine control unit. Proof is usually obtained within an exhaust gas test cycle run on a vehicle test stand. Furthermore, a minimum frequency for running the particular diagnostic method must be verified by internal counters within the control unit.
- Specifically this also requires detection of a defective engine temperature sensor as well as a sticking, faultily open coolant thermostat in the coolant circuit of the vehicle.
- Certain conventional methods diagnose the thermostat on the basis of a modeled expected temperature characteristic of the coolant temperature. These functions are based on models having relatively high tolerances. Therefore, a faultily open thermostat is detectable only when the deviation in the temperature characteristic from the modeled value is also relatively great.
- However, specifically in high-power, large-volume engines, there is the problem that they heat up relatively slowly in the exhaust gas test cycle and therefore the temperature difference between faultless operation and operation with a faultily open thermostat does not turn out to be great enough. Reliable diagnosis of a sticking, open thermostat is therefore impossible.
- A trip, during which a diagnostic sequence should be possible according to the statutory minimum requirements, results in a slight heating of the engine under some circumstances, so that a diagnosis is problematic.
- Example embodiments of the present invention provide a method that may ensure an adequate distance between measured and modeled temperatures, in particular during trips resulting in only slight heating of the engine.
- A method for diagnosing a faulty thermostat in a coolant circuit having a fan, in which the fan is turned on at least temporarily during the diagnosis, is particularly advantageous because the difference between the particular cooling effects in the case of a faulty thermostat and a faultless thermostat is particularly great due to the fan being turned on.
- The method may be particularly easy to implement if the thermostat is closed faultlessly.
- In addition, detection of a faulty thermostat is particularly simple if the faulty thermostat is detected as a function of a measured temperature and a setpoint temperature.
- Detection of a faulty thermostat is also particularly simple if the fan is triggered after a temperature increase in the coolant with respect to the ambient temperature which is to be defined.
- The method may be particularly reliable if the setpoint temperature is ascertained as a function of a second temperature sensed and/or as a function of the operating state of the internal combustion engine.
- The method may also be particularly reliable if a faulty thermostat is detected as a function of the curve of the first measured temperature and the curve of the setpoint temperature. It is also particularly expedient if a faulty thermostat is detected when the rise in the first measured temperature is slower than the rise in the setpoint temperature.
- The method may be economical in particular when the fan is turned on for the first time before reaching a predefinable temperature, in particular when this predefinable temperature is selected such that a faultless thermostat is still closed.
- The method may be inexpensive as an implementable measure because it does not require any additional cost. In particular no additional components, for example, sensors, need be provided.
- Further features and aspects of example embodiments of the present invention are described in more detail below with reference to the appended Figures.
-
FIG. 1 schematically illustrates an air-cooled coolant circuit having a fan. -
FIG. 2 schematically illustrates time curves of the temperatures with a faultless thermostat and a faultily open thermostat as well as the time curve of the triggering of the engine fan. -
FIG. 3 schematically illustrates the sequence of the diagnostic method. -
FIG. 1 showsinternal combustion engine 1, afirst coolant line 3, asecond coolant line 5 and athermostat 7.First coolant line 3 together with afirst connection 2 and asecond connection 6 forms a first coolant circuit ofinternal combustion engine 1.Second coolant line 5 together withfirst connection 2 andsecond connection 6, acooler 18, andthermostat 7 forms a second coolant circuit. The first coolant circuit and the second coolant circuit are filled with a coolant such as water.Thermostat 7 switches between first coolant circuit and second coolant circuit. Thermostat 7 is closed at low temperatures and coolant flows through the first coolant circuit and throughinternal combustion engine 1. Thermostat 7 is opened at high temperatures and coolant flows throughsecond coolant circuit 5 and throughinternal combustion engine 1. - The first coolant circuit, like
internal combustion engine 1, is in afirst area 10, which is at afirst temperature 12.Second coolant circuit 5 flows throughfirst area 10 as well as asecond area 14, which is at asecond temperature 16. After prolonged operation ofinternal combustion engine 1 in particular,first temperature 12 is definitely higher thansecond temperature 16. -
Thermostat 7 is closed when the value offirst temperature 12 is below a thermostat-specific threshold temperature. Whenthermostat 7 is closed, the coolant circulates in the first coolant circuit. There is no cooling by the first coolant circuit.Thermostat 7 opens when the value offirst temperature 12 exceeds the threshold temperature. Whenthermostat 7 is open, coolant circulates in the second coolant circuit. Cooling of the coolant therefore takes place incooler 18 due to heat exchange with the air insecond area 14. The temperature of the coolant is now lower thanfirst temperature 12 infirst area 10 and thus withdraws heat fromfirst area 10 via a heat exchange. -
FIG. 1 also shows adiagnostic unit 20, which detects whetherthermostat 7 is operating faultlessly. In the illustrated exemplary embodiment, athermostat 7 which is operating faultlessly would be closed and coolant should flow through the first coolant circuit. However, in this exemplary embodiment,thermostat 7 is faultily opened, i.e., coolant flows through the second coolant circuit.Diagnostic unit 20 detects thatthermostat 7 is faultily opened. -
Diagnostic unit 20 includes acalculation unit 22, acomparator unit 24 and a triggeringunit 26.FIG. 1 also shows a temperature sensor 30 and anengine fan 32. Temperature sensor 30 sensesfirst temperature 12 and relays this temperature tocalculation unit 22 andcomparator unit 24. The value of this first sensed and relayedtemperature 12 is referred to as a measuredtemperature 31.FIG. 1 also shows atemperature sensor 39, which sensessecond temperature 16 and relays it tocalculation unit 22. The value of this sensed relayedtemperature 16 is referred to as ascertainedambient temperature 41. - Triggering
unit 26controls engine fan 32 via a triggeringsignal 34. For example, triggeringsignal 34 may assume “on” and “off” values. If triggeringsignal 34 is “on,”engine fan 32 is induced to arotational movement 36. In this manner, cool air, which is still atsecond temperature 16, is conveyed into the vicinity ofcooler 18 and thus the cooling effect of coolant flowing through the second coolant circuit is increased. - In addition to measured
temperature 31,calculation unit 22 receivesengine variables 40 from adata unit 38 assigned tointernal combustion engine 1, these variables characterizing the prevailing operating state ofinternal combustion engine 1. Such an engine variable may be in particular the air mass combusted in the internal combustion engine. This is a measure of the total heat generated by the internal combustion engine since a reference point in time (for example, the point in time of the start of the internal combustion engine) and is also a measure of the heating of the internal combustion engine.Data unit 38 may be, for example, a sensor, an engine control unit, or a memory unit of an engine control unit. -
Calculation unit 22 ascertains asetpoint temperature 42 fromengine variables 40 and measuredtemperature 31 and relays it tocomparator unit 24. -
Setpoint temperature 42 corresponds to the expected measured temperature whenthermostat 7 is operating faultlessly.Comparator unit 24 checks the deviation in measuredtemperature 31 fromsetpoint temperature 42 and decides thatthermostat 7 is defective if the deviation between measuredtemperature 31 andsetpoint temperature 42 is too great.Setpoint temperature 42 is calculated incalculation unit 22 with the aid of a model ofinternal combustion engine 1, for example, which continuously calculates the expected temperature, i.e.,setpoint temperature 42, fromengine variables 40 and measuredtemperature 31. - The model first calculates, for example, the heat generated in
internal combustion engine 1 by using thermodynamic equations. In a next step, the model calculates the thermal output released by radiation, convection and optionally also thermal conduction and calculates expectedsetpoint temperature 42 from the heat balance. It is also possible for the model to ascertain expectedsetpoint temperature 42 with the aid of characteristic curves and characteristic maps, for example, taking into account measuredengine variables 40 and measured ambient conditions (for example, ascertained ambient temperature 41). -
FIG. 2 shows the curve of measuredtemperature 31 andsetpoint temperature 42 for the case whenthermostat 7 should be closed faultlessly but in fact is faultily open. Time t is plotted on the abscissa and temperature T is plotted on the ordinate. The time curve ofsetpoint temperature 42, shown inFIG. 2 , is calculated bycalculation unit 22 under the assumption of a faultlesslyclosed thermostat 7. The curve of measuredtemperature 31 with faultilyopen thermostat 7 andengine fan 32 at rest is labeled with reference numeral 31 a. At a reference point intime 70, instantaneous setpoint temperature Tsetpoint is compared with measured temperature Tdef. Measured temperature Tdef oftemperature curve 31 a is labeled withreference numeral 82. - The deviation between Tsetpoint and Tdef may have various causes. Possible causes include, for example but not exclusively, errors in the model used in
calculation unit 22, measurement errors or inaccuracies in temperature sensor 30 in ascertaining measuredtemperature 31 or a faultily openedthermostat 7. The decision thatthermostat 7 is defectively open is therefore possible only if measured temperature Tdef is lower than setpoint temperature Tsetpoint by aminimum temperature difference 84. At a sufficiently lowfirst temperature 12, the temperature difference fromsecond temperature 16 is small, the cooling effect of cooler 18 is thus minor, and a defectivelyopen thermostat 7 is not to be differentiated reliably from a correctlyclosed thermostat 7 by the difference between setpoint temperature Tsetpoint and measured temperature Tdef. This case is illustrated inFIG. 2 a. -
FIG. 2 b shows the time curve of triggeringsignal 34. At the start of the diagnosis, triggeringsignal 34 corresponds to the “off” value.Engine fan 32 is thus not in motion. Sincethermostat 7 is (faultily) opened, coolant is flowing through the second coolant circuit. At a first point in time 90, triggeringunit 26switches triggering signal 34 to “on.”Engine fan 32 then begins to move and increases the cooling power of cooler 18. The particular curve of measuredtemperature 31 is plotted inFIG. 2 a usingreference numeral 31 b. In comparison withtemperature curve 31 a whenengine fan 32 is at rest, the temperature oftemperature curve 31 b is much lower. The temperature oftemperature curve 31 b is all the lower, the lowerambient temperature 41 is and the greater the volume flow is created by the fan. - At a second point in
time 92, which may be before or after reference point intime 70, triggeringunit 26 againswitches triggering signal 34 from “on” to “off.” At reference point intime 70, the value of measuredtemperature 31 indicated using reference numeral 86 is now different from setpoint temperature Tsetpoint by more thanminimum temperature difference 84. Therefore, a defectively open thermostat is detected. - Reference point in
time 70, first point in time 90, and second point intime 92 may be ascertained by taking into account additional variables, for example, in particular the air mass combusted in the internal combustion engine, integrated over time. Second point intime 92 may also be selected in relation to first point in time 90, such that the time difference between second point intime 92 and first point in time 90 exceeds a predefinable time difference as a function of the characteristic offan 32 and a characteristic cooling power of the second coolant circuit. -
FIG. 3 shows as an example the sequence of the diagnostic procedure indiagnostic unit 20. Instep 200, the internal combustion engine is in the normal operating mode. At a point intime 202, there is a check as to whether a diagnosis is necessary (for example, because the last diagnosis was more than a predefined period of time in the past) and whether the diagnostic method may be used, for example, because measuredtemperature 31 is lower than a predefinable temperature. This predefinable temperature should in particular be lower than the threshold temperature ofthermostat 7, so that the thermostat is closed faultlessly. This predefinable temperature may also be reduced in comparison with the threshold temperature, for example, by the maximum increase in measuredtemperature 31 to be expected throughinternal combustion engine 1 during the diagnostic procedure or to compensate for exemplary scattering, in particular of the thermostat but also of other components. - If these conditions are met, the method branches off to step 204; if these conditions are not met, the method branches back to
step 200. The diagnostic method begins instep 204 and the model incalculation unit 22 is initialized. Step 206 then follows. - In
step 206 it is checked whether the time is already more advanced than first point in time 90. Alternatively, it may also check instep 206 whether the difference between measuredtemperature 31 and ascertainedambient temperature 41 is greater than a predefinable temperature difference. The predefinable temperature difference must be selected as a function of the characteristics offan 32, such that in the case of a faulty fan, the difference between setpoint temperature Tsetpoint and ascertained temperature 86 becomes large enough. - If this is the case, the method branches to step 208. If this is not the case, it jumps back to
step 206. - In
step 208, triggeringunit 26switches triggering signal 34 to “on.” This is followed bystep 210. Instep 210, it is checked whether the time has already exceeded second point intime 92. Alternatively, instep 210 it may also be checked whether the integrated air mass combusted in the engine has exceeded an air mass threshold value. This air mass threshold value must be selected such that it ensures that the engine has warmed up sufficiently for the expected difference between setpoint temperature Tsetpoint and measured temperature Tdef to become large enough in the case of a defectively open thermostat. As another alternative, it may also be checked instep 210 whether temperature difference Tsetpoint−Tdef is already greater thanminimum temperature difference 84. If this is the case, the method branches further to step 212. If this is not the case, it jumps back tostep 210. - In
step 212, triggeringunit 26switches triggering signal 34 to “off” and branches further to step 214. Instep 214, it is checked whether the instantaneous point in time is later than reference point intime 70. If this is the case,step 216 follows. If this is not the case, the method jumps back tostep 214. Instep 216calculation unit 22 calculatessetpoint temperature 42 continuously, for example, and relays it tocomparator unit 24. Temperature sensor 30 likewise relays measuredtemperature 31 tocomparator unit 24.Comparator unit 24 then calculates the difference between setpoint temperature Tsetpoint and measured temperature Tdef. Step 218 then follows in sequence. Instep 218 it is checked whether difference Tsetpoint Tdef is greater than the predefinable minimum temperature difference. If this is the case,step 220 follows. If this is not the case,step 200 follows again. The diagnostic procedure ends at the end ofstep 218. Instep 220, a faultily open thermostat is now diagnosed. Next an error flag for the engine control unit may be set, for example, setting the engine in emergency operation or outputting an acoustic or visual warning for the driver. - Since reference point in
time 70 may be either before or after second point intime 92, the sequence ofsteps step 208, it is thus possible to branch off to step 214, fromstep 216 to 210 and fromstep 212 to step 218. - Instead of
internal combustion engine 1, any other heat-generating machine may also be used, for example, a fuel cell or a battery. - The comparison of measured
temperature 31 andsetpoint temperature 42 performed incomparator unit 24 may also take into account the temperatures at more than one reference point intime 70. For example, it is possible to use the integrated difference between measuredtemperature 31 andsetpoint temperature 42 during a comparative period of time to detect a defectively open thermostat. - It is also possible to diagnose a defectively
closed thermostat 7. In this case, the model of the temperature trend present incalculation unit 22 must also take into account the influence ofrotating engine fan 32. Unlike the exemplary embodiment described here, in which a defectively open thermostat is identified by an unexpectedly high cooling performance, a defectively closed thermostat may be identified by an unexpectedly low cooling performance.
Claims (11)
1. A method for diagnosing a thermostat in a coolant circuit, comprising:
detecting a faulty thermostat as a function of a measured temperature and a setpoint temperature; and
turning on a fan of the cooling circuit at least temporarily during the detecting.
2. The method according to claim 1 , wherein the cooling circuit is arranged as a cooling circuit of an internal combustion engine.
3. The method according to claim 1 , wherein the thermostat is closed faultlessly.
4. The method according to claim 1 , wherein the setpoint temperature is ascertained as a function of at least one of (a) the measured temperature and (b) characteristic variables of an internal combustion engine that includes the coolant circuit.
5. The method according to claim 1 , wherein the thermostat is detected as faulty as a function of a curve of the measured temperature and a curve of the setpoint temperature.
6. The method according to claim 5 , wherein the thermostat is detected as faulty when an increase of the measured temperature is slower than an increase of the setpoint temperature.
7. The method according to claim 1 , wherein the fan is turned on for a first time before the measured temperature reaches a predefinable temperature.
8. The method according to claim 7 , wherein the predefinable temperature is a threshold temperature at which the thermostat begins to open in a faultless state.
9. The method according to claim 1 , wherein the fan is turned on when a difference between the measured temperature and an ascertained ambient temperature is greater than a predefinable temperature difference.
10. A non-transitory computer-readable storage medium with an executable program stored thereon, wherein the program instructs a microprocessor to perform a method for diagnosing a thermostat in a coolant circuit, including:
detecting a faulty thermostat as a function of a measured temperature and a setpoint temperature; and
turning on a fan of the cooling circuit at least temporarily during the detecting.
11. A system, comprising:
a diagnostic device of a thermostat of a coolant circuit, the diagnostic device adapted to perform a method including:
detecting a faulty thermostat as a function of a measured temperature and a setpoint temperature; and
turning on a fan of the cooling circuit at least temporarily during the detecting.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102010001618.7 | 2010-02-05 | ||
DE102010001618A DE102010001618A1 (en) | 2010-02-05 | 2010-02-05 | Method for diagnosing thermostat in air-cooled refrigerant circuit of combustion engine in motor car, involves switching on fan temporarily during diagnostic process before measured temperature reaches predeterminable temperature |
Publications (1)
Publication Number | Publication Date |
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US20120033705A1 true US20120033705A1 (en) | 2012-02-09 |
Family
ID=44316369
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/016,478 Abandoned US20120033705A1 (en) | 2010-02-05 | 2011-01-28 | Method and device for diagnosing a thermostat |
Country Status (3)
Country | Link |
---|---|
US (1) | US20120033705A1 (en) |
CN (1) | CN102191994A (en) |
DE (1) | DE102010001618A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130319352A1 (en) * | 2012-06-04 | 2013-12-05 | Robert Bosch Gmbh | Method for lowering the air temperature of an engine compartment of a vehicle |
US20140123918A1 (en) * | 2012-11-07 | 2014-05-08 | Cummins Inc. | Method and system to diagnose thermostat failure in engine with onboard diagnostics |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
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US10060333B2 (en) * | 2016-05-02 | 2018-08-28 | Ford Global Technologies, Llc | Systems and methods for engine coolant system diagnostics |
US10662863B1 (en) * | 2018-11-20 | 2020-05-26 | Caterpillar Inc. | Systems and methods for monitoring the performance of a heat exchanger |
DE102020201920A1 (en) | 2020-02-17 | 2021-08-19 | Robert Bosch Gesellschaft mit beschränkter Haftung | Method for determining a system status, computer program product and device |
DE102021110134A1 (en) | 2021-04-21 | 2022-10-27 | Viessmann Climate Solutions Se | METHOD, CONTROL, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR CONTROLLING A HEATING AND/OR AIR CONDITIONING SYSTEM |
CN116271523B (en) * | 2022-12-30 | 2024-03-29 | 江苏海莱新创医疗科技有限公司 | Electrode sheet, electrode sheet identification method, tumor electric field treatment system and treatment equipment |
CN115845260A (en) * | 2022-12-30 | 2023-03-28 | 江苏海莱新创医疗科技有限公司 | Tumor electric field treatment system, electrode plate thereof and temperature detection method |
CN117665458A (en) * | 2022-12-30 | 2024-03-08 | 江苏海莱新创医疗科技有限公司 | Electrode slice, tumor treatment equipment and electrode slice fault detection method |
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US4407141A (en) * | 1982-01-04 | 1983-10-04 | Whirlpool Corporation | Temperature sensing means for refrigerator |
US6463892B1 (en) * | 2000-03-15 | 2002-10-15 | Ford Global Technologies, Inc. | Method for detecting cooling system faults |
US20100095909A1 (en) * | 2008-10-22 | 2010-04-22 | Caterpillar Inc. | Engine cooling system onboard diagnostic strategy |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
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DE19958384A1 (en) * | 1999-12-03 | 2001-06-07 | Bosch Gmbh Robert | Process for detecting a faulty sensor |
DE10001713A1 (en) * | 2000-01-18 | 2001-07-19 | Bosch Gmbh Robert | Fault detection in cooling system for motor vehicle engine involves comparing variation of actual temperature with two model temperature ranges to determine if fault is in sensor or valve |
DE102005048313B4 (en) * | 2005-10-06 | 2013-10-10 | Iav Gmbh Ingenieurgesellschaft Auto Und Verkehr | Method for diagnosing the condition of a thermostat |
-
2010
- 2010-02-05 DE DE102010001618A patent/DE102010001618A1/en not_active Ceased
-
2011
- 2011-01-28 US US13/016,478 patent/US20120033705A1/en not_active Abandoned
- 2011-02-01 CN CN2011100342753A patent/CN102191994A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4407141A (en) * | 1982-01-04 | 1983-10-04 | Whirlpool Corporation | Temperature sensing means for refrigerator |
US6463892B1 (en) * | 2000-03-15 | 2002-10-15 | Ford Global Technologies, Inc. | Method for detecting cooling system faults |
US20100095909A1 (en) * | 2008-10-22 | 2010-04-22 | Caterpillar Inc. | Engine cooling system onboard diagnostic strategy |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130319352A1 (en) * | 2012-06-04 | 2013-12-05 | Robert Bosch Gmbh | Method for lowering the air temperature of an engine compartment of a vehicle |
US20140123918A1 (en) * | 2012-11-07 | 2014-05-08 | Cummins Inc. | Method and system to diagnose thermostat failure in engine with onboard diagnostics |
US9605584B2 (en) * | 2012-11-07 | 2017-03-28 | Cummins Inc. | Method and system to diagnose thermostat failure in engine with onboard diagnostics |
Also Published As
Publication number | Publication date |
---|---|
DE102010001618A1 (en) | 2011-08-11 |
CN102191994A (en) | 2011-09-21 |
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AS | Assignment |
Owner name: ROBERT BOSCH GMBH, GERMANY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:WILTSCH, PETER;REEL/FRAME:026068/0538 Effective date: 20110321 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |